1. Field of the Invention
The present invention relates generally to a radio communications repeater, and more particularly relates to a radio communications repeater system for high-speed data communication which enables multiple users to access a common geographically distributed radio channel.
2. Description of the Prior Art
Radio communication repeater systems receive radio signals, amplify the signals and retransmit the signals to a distant location. One type of radio communication repeater system is a half-duplex system. The half-duplex system is incapable of simultaneously transmitting and receiving radio signals. This results in a reduction of throughput rate by a factor of two, since the repeater system must first receive signals from a host radio and then retransmit the signals to another repeater or a user. Throughput is further reduced when extended coverage continues through a series of repeaters.
Another type of repeater system is a full-duplex system. Full-duplex systems use one radio channel for reception and a second radio channel for transmission. This type of repeater system does not suffer the throughput rate limitation described in the half-duplex radio system. However, to achieve necessary channel isolation, the frequencies are normally widely separated and assigned by the United States Government Federal Communications Commission (FCC) in channel pairs. The bandwidth is fixed or constrained to a single channel. The full-duplex method can be achieved by segregating the single channel into transmit and receive time slots, which reduces the possible data throughput by one-half.
One method to regain lost data transmission throughput is to encode the communications data stream to fit more data into a fixed bandwidth. These encoding schemes require increasingly higher levels of communication channel signal-to-noise ratios, which in some applications can be realized by increasing the transmitter power by a factor of two or more. However, in many communication applications the FCC restricts the radio frequency power and the antenna directional characteristics which can be used in a radio channel. This limits the encoding of the communication data streams and the throughput rate.
Many communication applications require wireless multi-point access, in contrast to simple point-to-point data access. Wireless multi-point access requires a repeater to effectively serve multiple users simultaneously at remote locations. In this situation, the repeater cannot translate all communication signals from one side to the other and must allocate time slots in which the different remote radios can communicate with a host radio. This is achieved by a process known as polling. Polling leads to inefficient spectrum utilization because time slots go unused when a polled radio has no data to transfer.
Additionally, there are radio communication applications where extended coverage areas are desired and line-of-sight conditions do not exist. This problem is typically circumvented using high radio towers to establish line-of-sight conditions. Radio towers are expensive to construct, and are located many miles apart. Radio transmitters to reach the longer range between radio towers may require higher transmit power than is allowed by the FCC. Moreover, use of highly directional antennas may restrict use to point-to-point only, precluding multi-point applications. Hence, the use of a non-tower based radio communication repeater station may be the only alternative, even though it lacks full data speed throughput and cannot operate in a multi-point access mode.
Thus, the present invention is directed towards overcoming the disadvantages of conventional radio communication repeaters and multi-point access radio communication repeaters.
It is an object of the present invention to provide a low cost, compact repeater for radio communications.
It is another object of the present invention to provide a radio communications repeater which is capable of full data rate transfers in half-duplex systems.
It is a further object of the present invention to provide a radio communications repeater which can support multi-communication protocols, including but not limited to TCP/IP and Ethernet.
It is still another object of the present invention to provide a radio communications repeater which provides for multi-user access for both remote wireless systems and locally wired systems to the repeater site.
It is yet another object of the present invention to provide the ability to segment data traffic onto two or more separate segments, through the use of frequency channel separation, data stream encoding and/or spacial separation techniques (antenna radiation pattern separation).
It is yet another object of the present invention to provide for remote monitoring and maintenance for controlling of a radio communications repeater.
It is yet another object of the present invention to act as a firewall to isolate remote segments.
It is yet another object of the present invention to enable burstable data communication protocols to enhance data distributions to users in a multi-user (access) environment which effectively provides high communication speeds.
A wireless high speed data communication system constructed in accordance with one form of the present invention includes a host radio station connected to a source of data. The host radio station transmits and receives data to and from at least one wireless communication repeater within line of sight of the host radio station. The repeater is configured to communicate with at least one end user by either a direct electrical connection or a wireless connection. The repeater may also transmit and receive data to another repeater within its line of sight yet beyond the line of sight of the host radio station. The data source, connected to the host radio station, can be private data or data accessed and/or delivered to the Internet.
The repeater has at least one radio/data link element for receiving and transmitting data packets between the repeater and the host radio station. A processor controls the data flow within the repeater. Data may be communicated between the repeater and the host radio station, the repeater and the users, and the repeater and the other repeaters. The repeater communicates with the end users through a direct electrical connection and/or a wireless connection. Additional radio transceivers may be included in the repeater to communicate the data from the host radio station to a second repeater.
A method of routing data in the form of packets formed in accordance with the present invention includes the steps of receiving data packets by a radio/data link element of a repeater and using a forwarding engine TCP/IP stack to route data packets via a packet exchange bus to their proper addresses. The method may also include filtering out IP addresses which are not programmed to be received, and may include the step of monitoring data packets for the purpose of accounting.